FAULTS: THRUST / REVERSE
THRUST / REVERSE FAULTS
DESCRIPTION: Reverse Faults are those in which the Hanging Wall has moved up with respect to the Foot Wall. A Thrust Fault is a low angle Reverse Fault. Due to the low angle, it is not uncommon for older rock to be shoved long distances OVER younger rock.
Figure 1 - Three Peaks of Chetamon in Jasper National Park
DESCRIPTION - Normal Faults are those in which the Hanging Wall slides down the inclined fault plane with respect to the Foot Wall. These type of faults are caused by Tensional forces pulling apart the earth.
DESCRIPTION: A fault escarpment (or scarp) is a surface separating a down dropped from an upthrown block.
Figure 1 - THE WASATCH FAULT ESCARPMENT. The Wasatch Fault runs parallel to the Wasatch Mountains to the east. It is actually a series of about 10 fault segments of which about 5 are active. The faults run about 220 miles between southeast Idaho to central Utah. The fault plane dips to the west. Normal faulting has resulted in mountains to the east of the fault and valleys of the Basin and Range Province to the west. Over the past 10,000 years, earthquakes of magnitude 7+ occur about every 1000 years.